const THREE = require('../../three.js');

(function () {

	/**
 * Loads a Wavefront .mtl file specifying materials
 */

	class MTLLoader extends THREE.Loader {

		constructor(manager) {

			super(manager);

		}
		/**
   * Loads and parses a MTL asset from a URL.
   *
   * @param {String} url - URL to the MTL file.
   * @param {Function} [onLoad] - Callback invoked with the loaded object.
   * @param {Function} [onProgress] - Callback for download progress.
   * @param {Function} [onError] - Callback for download errors.
   *
   * @see setPath setResourcePath
   *
   * @note In order for relative texture references to resolve correctly
   * you must call setResourcePath() explicitly prior to load.
   */


		load(url, onLoad, onProgress, onError) {

			const scope = this;
			const path = this.path === '' ? THREE.LoaderUtils.extractUrlBase(url || '') : this.path;
			const loader = new THREE.FileLoader(this.manager);
			loader.setPath(this.path);
			loader.setRequestHeader(this.requestHeader);
			loader.setWithCredentials(this.withCredentials);
			loader.load(url, function (text) {

				try {

					onLoad(scope.parse(text, path));

				} catch (e) {

					if (onError) {

						onError(e);

					} else {

						console.error(e);

					}

					scope.manager.itemError(url);

				}

			}, onProgress, onError);

		}

		setMaterialOptions(value) {

			this.materialOptions = value;
			return this;

		}
		/**
   * Parses a MTL file.
   *
   * @param {String} text - Content of MTL file
   * @return {MaterialCreator}
   *
   * @see setPath setResourcePath
   *
   * @note In order for relative texture references to resolve correctly
   * you must call setResourcePath() explicitly prior to parse.
   */


		parse(text, path) {

			const lines = text.split('\n');
			let info = {};
			const delimiter_pattern = /\s+/;
			const materialsInfo = {};

			for (let i = 0; i < lines.length; i++) {

				let line = lines[i];
				line = line.trim();

				if (line.length === 0 || line.charAt(0) === '#') {

					// Blank line or comment ignore
					continue;

				}

				const pos = line.indexOf(' ');
				let key = pos >= 0 ? line.substring(0, pos) : line;
				key = key.toLowerCase();
				let value = pos >= 0 ? line.substring(pos + 1) : '';
				value = value.trim();

				if (key === 'newmtl') {

					// New material
					info = {
						name: value
					};
					materialsInfo[value] = info;

				} else {

					if (key === 'ka' || key === 'kd' || key === 'ks' || key === 'ke') {

						const ss = value.split(delimiter_pattern, 3);
						info[key] = [parseFloat(ss[0]), parseFloat(ss[1]), parseFloat(ss[2])];

					} else {

						info[key] = value;

					}

				}

			}

			const materialCreator = new MaterialCreator(this.resourcePath || path, this.materialOptions);
			materialCreator.setCrossOrigin(this.crossOrigin);
			materialCreator.setManager(this.manager);
			materialCreator.setMaterials(materialsInfo);
			return materialCreator;

		}

	}
	/**
 * Create a new MTLLoader.MaterialCreator
 * @param baseUrl - Url relative to which textures are loaded
 * @param options - Set of options on how to construct the materials
 *                  side: Which side to apply the material
 *                        THREE.FrontSide (default), THREE.BackSide, THREE.DoubleSide
 *                  wrap: What type of wrapping to apply for textures
 *                        THREE.RepeatWrapping (default), THREE.ClampToEdgeWrapping, THREE.MirroredRepeatWrapping
 *                  normalizeRGB: RGBs need to be normalized to 0-1 from 0-255
 *                                Default: false, assumed to be already normalized
 *                  ignoreZeroRGBs: Ignore values of RGBs (Ka,Kd,Ks) that are all 0's
 *                                  Default: false
 * @constructor
 */


	class MaterialCreator {

		constructor(baseUrl = '', options = {}) {

			this.baseUrl = baseUrl;
			this.options = options;
			this.materialsInfo = {};
			this.materials = {};
			this.materialsArray = [];
			this.nameLookup = {};
			this.crossOrigin = 'anonymous';
			this.side = this.options.side !== undefined ? this.options.side : THREE.FrontSide;
			this.wrap = this.options.wrap !== undefined ? this.options.wrap : THREE.RepeatWrapping;

		}

		setCrossOrigin(value) {

			this.crossOrigin = value;
			return this;

		}

		setManager(value) {

			this.manager = value;

		}

		setMaterials(materialsInfo) {

			this.materialsInfo = this.convert(materialsInfo);
			this.materials = {};
			this.materialsArray = [];
			this.nameLookup = {};

		}

		convert(materialsInfo) {

			if (!this.options) return materialsInfo;
			const converted = {};

			for (const mn in materialsInfo) {

				// Convert materials info into normalized form based on options
				const mat = materialsInfo[mn];
				const covmat = {};
				converted[mn] = covmat;

				for (const prop in mat) {

					let save = true;
					let value = mat[prop];
					const lprop = prop.toLowerCase();

					switch (lprop) {

						case 'kd':
						case 'ka':
						case 'ks':
							// Diffuse color (color under white light) using RGB values
							if (this.options && this.options.normalizeRGB) {

								value = [value[0] / 255, value[1] / 255, value[2] / 255];

							}

							if (this.options && this.options.ignoreZeroRGBs) {

								if (value[0] === 0 && value[1] === 0 && value[2] === 0) {

									// ignore
									save = false;

								}

							}

							break;

						default:
							break;

					}

					if (save) {

						covmat[lprop] = value;

					}

				}

			}

			return converted;

		}

		preload() {

			for (const mn in this.materialsInfo) {

				this.create(mn);

			}

		}

		getIndex(materialName) {

			return this.nameLookup[materialName];

		}

		getAsArray() {

			let index = 0;

			for (const mn in this.materialsInfo) {

				this.materialsArray[index] = this.create(mn);
				this.nameLookup[mn] = index;
				index++;

			}

			return this.materialsArray;

		}

		create(materialName) {

			if (this.materials[materialName] === undefined) {

				this.createMaterial_(materialName);

			}

			return this.materials[materialName];

		}

		createMaterial_(materialName) {

			// Create material
			const scope = this;
			const mat = this.materialsInfo[materialName];
			const params = {
				name: materialName,
				side: this.side
			};

			function resolveURL(baseUrl, url) {

				if (typeof url !== 'string' || url === '') return ''; // Absolute URL

				if (/^https?:\/\//i.test(url)) return url;
				return baseUrl + url;

			}

			function setMapForType(mapType, value) {

				if (params[mapType]) return; // Keep the first encountered texture

				const texParams = scope.getTextureParams(value, params);
				const map = scope.loadTexture(resolveURL(scope.baseUrl, texParams.url));
				map.repeat.copy(texParams.scale);
				map.offset.copy(texParams.offset);
				map.wrapS = scope.wrap;
				map.wrapT = scope.wrap;
				params[mapType] = map;

			}

			for (const prop in mat) {

				const value = mat[prop];
				let n;
				if (value === '') continue;

				switch (prop.toLowerCase()) {

					// Ns is material specular exponent
					case 'kd':
						// Diffuse color (color under white light) using RGB values
						params.color = new THREE.Color().fromArray(value);
						break;

					case 'ks':
						// Specular color (color when light is reflected from shiny surface) using RGB values
						params.specular = new THREE.Color().fromArray(value);
						break;

					case 'ke':
						// Emissive using RGB values
						params.emissive = new THREE.Color().fromArray(value);
						break;

					case 'map_kd':
						// Diffuse texture map
						setMapForType('map', value);
						break;

					case 'map_ks':
						// Specular map
						setMapForType('specularMap', value);
						break;

					case 'map_ke':
						// Emissive map
						setMapForType('emissiveMap', value);
						break;

					case 'norm':
						setMapForType('normalMap', value);
						break;

					case 'map_bump':
					case 'bump':
						// Bump texture map
						setMapForType('bumpMap', value);
						break;

					case 'map_d':
						// Alpha map
						setMapForType('alphaMap', value);
						params.transparent = true;
						break;

					case 'ns':
						// The specular exponent (defines the focus of the specular highlight)
						// A high exponent results in a tight, concentrated highlight. Ns values normally range from 0 to 1000.
						params.shininess = parseFloat(value);
						break;

					case 'd':
						n = parseFloat(value);

						if (n < 1) {

							params.opacity = n;
							params.transparent = true;

						}

						break;

					case 'tr':
						n = parseFloat(value);
						if (this.options && this.options.invertTrProperty) n = 1 - n;

						if (n > 0) {

							params.opacity = 1 - n;
							params.transparent = true;

						}

						break;

					default:
						break;

				}

			}

			this.materials[materialName] = new THREE.MeshPhongMaterial(params);
			return this.materials[materialName];

		}

		getTextureParams(value, matParams) {

			const texParams = {
				scale: new THREE.Vector2(1, 1),
				offset: new THREE.Vector2(0, 0)
			};
			const items = value.split(/\s+/);
			let pos;
			pos = items.indexOf('-bm');

			if (pos >= 0) {

				matParams.bumpScale = parseFloat(items[pos + 1]);
				items.splice(pos, 2);

			}

			pos = items.indexOf('-s');

			if (pos >= 0) {

				texParams.scale.set(parseFloat(items[pos + 1]), parseFloat(items[pos + 2]));
				items.splice(pos, 4); // we expect 3 parameters here!

			}

			pos = items.indexOf('-o');

			if (pos >= 0) {

				texParams.offset.set(parseFloat(items[pos + 1]), parseFloat(items[pos + 2]));
				items.splice(pos, 4); // we expect 3 parameters here!

			}

			texParams.url = items.join(' ').trim();
			return texParams;

		}

		loadTexture(url, mapping, onLoad, onProgress, onError) {

			const manager = this.manager !== undefined ? this.manager : THREE.DefaultLoadingManager;
			let loader = manager.getHandler(url);

			if (loader === null) {

				loader = new THREE.TextureLoader(manager);

			}

			if (loader.setCrossOrigin) loader.setCrossOrigin(this.crossOrigin);
			const texture = loader.load(url, onLoad, onProgress, onError);
			if (mapping !== undefined) texture.mapping = mapping;
			return texture;

		}

	}

	THREE.MTLLoader = MTLLoader;

})();

module.exports = exports = THREE.MTLLoader;